Kami, yes, I guess the TC fins are in the same spirit as the C-Drive: wide base and thin tip.
These short boards in small waves have tons of acceleration, one instant you are pushing (pumping) hard on the fins to accelerate at the bottom and you want hold, the other you are at full speed and do not want your fins to act as hydrofoils and stiffen the tail. So you want fins that can work in very different conditions.
As for the size, I like big fins in front as they are more forgiving in fickle beach breaks: if you see a bump forming in the wave in front of you you can set up a quick bottom with full force to hit the ramp. Bigger front fins will allow you to push hard on the board without having perfectly dug the rail before. But smaller fins are more efficient in that they free the board to follow its natural path on the wave.
Bigger front fins + smaller rear ones => oversteer, nice for controlled drifts all over the place :-)
With my 100kg, I was definitely losing power in bottom turns with Nexus in front for instance. But I use a Nexus thruster setup on longer (>8') boards where I can rely more on the rails.
On my current Fatal, I used:
XL C-Drive front, nexus rear quads. Fun & fast in small waves, some floating between turns in shoulder-high waves
XL C-Drive front, nexus rear quads, and a nubster: a setup that worked in other boards but not for this board, I could feel it always in turbulent flow (small wobbles in the back foot)
XL C-Drive front, nexus rear quads, and a trailer: tamer in the small waves, but can handle more size and power. The more forgiving setup, less performance than a thruster, but doesnt punish you when you botch a bit your turns in the size
XL C-Drive thruster, the most all-around, but the wide tail means you must be careful to dig properly the rear rail in tuns in the size
And for the fun, my config for my small-wave rocket (the Gong One). Had a blast yesterday in small, clean waves